diff --git a/.changelog/4606.txt b/.changelog/4606.txt
new file mode 100644
index 0000000000..0b27a3f2ef
--- /dev/null
+++ b/.changelog/4606.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+bigquery: fixed issue where you couldn't extend an existing `schema` with additional columns in `google_bigquery_table`
+```
diff --git a/google-beta/resource_bigquery_table.go b/google-beta/resource_bigquery_table.go
index 8f9d2fde0f..abb46b7703 100644
--- a/google-beta/resource_bigquery_table.go
+++ b/google-beta/resource_bigquery_table.go
@@ -21,6 +21,15 @@ func bigQueryTableSortArrayByName(array []interface{}) {
 	})
 }
 
+func bigQueryArrayToMapIndexedByName(array []interface{}) map[string]interface{} {
+	out := map[string]interface{}{}
+	for _, v := range array {
+		name := v.(map[string]interface{})["name"].(string)
+		out[name] = v
+	}
+	return out
+}
+
 func bigQueryTablecheckNameExists(jsonList []interface{}) error {
 	for _, m := range jsonList {
 		if _, ok := m.(map[string]interface{})["name"]; !ok {
@@ -197,14 +206,18 @@ func resourceBigQueryTableSchemaIsChangeable(old, new interface{}) (bool, error)
 		if err := bigQueryTablecheckNameExists(arrayOld); err != nil {
 			return false, err
 		}
-		bigQueryTableSortArrayByName(arrayOld)
+		mapOld := bigQueryArrayToMapIndexedByName(arrayOld)
 		if err := bigQueryTablecheckNameExists(arrayNew); err != nil {
 			return false, err
 		}
-		bigQueryTableSortArrayByName(arrayNew)
-		for i := range arrayOld {
+		mapNew := bigQueryArrayToMapIndexedByName(arrayNew)
+		for key := range mapOld {
+			// all old keys should be represented in the new config
+			if _, ok := mapNew[key]; !ok {
+				return false, nil
+			}
 			if isChangable, err :=
-				resourceBigQueryTableSchemaIsChangeable(arrayOld[i], arrayNew[i]); err != nil || !isChangable {
+				resourceBigQueryTableSchemaIsChangeable(mapOld[key], mapNew[key]); err != nil || !isChangable {
 				return false, err
 			}
 		}
@@ -216,7 +229,6 @@ func resourceBigQueryTableSchemaIsChangeable(old, new interface{}) (bool, error)
 			// if both aren't objects
 			return false, nil
 		}
-
 		var unionOfKeys map[string]bool = make(map[string]bool)
 		for key := range objectOld {
 			unionOfKeys[key] = true
@@ -224,7 +236,6 @@ func resourceBigQueryTableSchemaIsChangeable(old, new interface{}) (bool, error)
 		for key := range objectNew {
 			unionOfKeys[key] = true
 		}
-
 		for key := range unionOfKeys {
 			valOld := objectOld[key]
 			valNew := objectNew[key]
diff --git a/google-beta/resource_bigquery_table_test.go b/google-beta/resource_bigquery_table_test.go
index 3d8fdcc983..8521b7c586 100644
--- a/google-beta/resource_bigquery_table_test.go
+++ b/google-beta/resource_bigquery_table_test.go
@@ -509,6 +509,39 @@ func TestAccBigQueryDataTable_canReorderParameters(t *testing.T) {
 	})
 }
 
+func TestAccBigQueryDataTable_expandArray(t *testing.T) {
+	t.Parallel()
+
+	datasetID := fmt.Sprintf("tf_test_%s", randString(t, 10))
+	tableID := fmt.Sprintf("tf_test_%s", randString(t, 10))
+
+	vcrTest(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckBigQueryTableDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccBigQueryTable_arrayInitial(datasetID, tableID),
+			},
+			{
+				ResourceName:            "google_bigquery_table.test",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"etag", "last_modified_time", "deletion_protection"},
+			},
+			{
+				Config: testAccBigQueryTable_arrayExpanded(datasetID, tableID),
+			},
+			{
+				ResourceName:            "google_bigquery_table.test",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"etag", "last_modified_time", "deletion_protection"},
+			},
+		},
+	})
+}
+
 func TestUnitBigQueryDataTable_jsonEquivalency(t *testing.T) {
 	t.Parallel()
 
@@ -632,12 +665,12 @@ var testUnitBigQueryDataTableIsChangableTestCases = []testUnitBigQueryDataTableJ
 	{
 		name:       "arraySizeIncreases",
 		jsonOld:    "[{\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }]",
-		jsonNew:    "[{\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }, {\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }]",
+		jsonNew:    "[{\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }, {\"name\": \"asomeValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }]",
 		changeable: true,
 	},
 	{
 		name:       "arraySizeDecreases",
-		jsonOld:    "[{\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }, {\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }]",
+		jsonOld:    "[{\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }, {\"name\": \"asomeValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }]",
 		jsonNew:    "[{\"name\": \"someValue\", \"type\" : \"INTEGER\", \"mode\" : \"NULLABLE\", \"description\" : \"someVal\" }]",
 		changeable: false,
 	},
@@ -1630,6 +1663,79 @@ resource "google_bigquery_table" "test" {
 `, datasetID, tableID)
 }
 
+func testAccBigQueryTable_arrayInitial(datasetID, tableID string) string {
+	return fmt.Sprintf(`
+resource "google_bigquery_dataset" "test" {
+  dataset_id = "%s"
+}
+
+resource "google_bigquery_table" "test" {
+  deletion_protection = false
+  table_id   = "%s"
+  dataset_id = google_bigquery_dataset.test.dataset_id
+
+  friendly_name = "bigquerytest"
+  labels = {
+    "terrafrom_managed" = "true"
+  }
+
+  schema = jsonencode(
+    [
+      {
+        description = "Time snapshot was taken, in Epoch milliseconds. Same across all rows and all tables in the snapshot, and uniquely defines a particular snapshot."
+        name        = "snapshot_timestamp"
+        mode        = "NULLABLE"
+        type        = "INTEGER"
+      },
+      {
+        description = "Timestamp of dataset creation"
+        name        = "creation_time"
+        type        = "TIMESTAMP"
+      },
+    ])
+}
+`, datasetID, tableID)
+}
+
+func testAccBigQueryTable_arrayExpanded(datasetID, tableID string) string {
+	return fmt.Sprintf(`
+resource "google_bigquery_dataset" "test" {
+  dataset_id = "%s"
+}
+
+resource "google_bigquery_table" "test" {
+  deletion_protection = false
+  table_id   = "%s"
+  dataset_id = google_bigquery_dataset.test.dataset_id
+
+  friendly_name = "bigquerytest"
+  labels = {
+    "terrafrom_managed" = "true"
+  }
+
+  schema = jsonencode(
+    [
+      {
+        description = "Time snapshot was taken, in Epoch milliseconds. Same across all rows and all tables in the snapshot, and uniquely defines a particular snapshot."
+        name        = "snapshot_timestamp"
+        mode        = "NULLABLE"
+        type        = "INTEGER"
+      },
+      {
+        description = "Timestamp of dataset creation"
+        name        = "creation_time"
+        type        = "TIMESTAMP"
+      },
+			{
+        description = "some new value"
+        name        = "a_new_value"
+        type        = "TIMESTAMP"
+      },
+    ])
+}
+`, datasetID, tableID)
+}
+
 var TEST_CSV = `lifelock,LifeLock,,web,Tempe,AZ,1-May-07,6850000,USD,b
 lifelock,LifeLock,,web,Tempe,AZ,1-Oct-06,6000000,USD,a
 lifelock,LifeLock,,web,Tempe,AZ,1-Jan-08,25000000,USD,c